drivers/mmc/core/regulator.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Helper functions for MMC regulators.
  */

 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/log2.h>
 #include <linux/regulator/consumer.h>

 #include <linux/mmc/host.h>

 #include "core.h"
 #include "host.h"

 #ifdef CONFIG_REGULATOR

 /**
  * mmc_ocrbitnum_to_vdd - Convert a OCR bit number to its voltage
  * @vdd_bit:	OCR bit number
  * @min_uV:	minimum voltage value (mV)
  * @max_uV:	maximum voltage value (mV)
  *
  * This function returns the voltage range according to the provided OCR
  * bit number. If conversion is not possible a negative errno value returned.
  */
 static int mmc_ocrbitnum_to_vdd(int vdd_bit, int *min_uV, int *max_uV)
 {
 	int		tmp;

 	if (!vdd_bit)
 		return -EINVAL;

 	/*
 	 * REVISIT mmc_vddrange_to_ocrmask() may have set some
 	 * bits this regulator doesn't quite support ... don't
 	 * be too picky, most cards and regulators are OK with
 	 * a 0.1V range goof (it's a small error percentage).
 	 */
 	tmp = vdd_bit - ilog2(MMC_VDD_165_195);
 	if (tmp == 0) {
 		*min_uV = 1650 * 1000;
 		*max_uV = 1950 * 1000;
 	} else {
 		*min_uV = 1900 * 1000 + tmp * 100 * 1000;
 		*max_uV = *min_uV + 100 * 1000;
 	}

 	return 0;
 }

 /**
  * mmc_regulator_get_ocrmask - return mask of supported voltages
  * @supply: regulator to use
  *
  * This returns either a negative errno, or a mask of voltages that
  * can be provided to MMC/SD/SDIO devices using the specified voltage
  * regulator.  This would normally be called before registering the
  * MMC host adapter.
  */
 static int mmc_regulator_get_ocrmask(struct regulator *supply)
 {
 	int			result = 0;
 	int			count;
 	int			i;
 	int			vdd_uV;
 	int			vdd_mV;

 	count = regulator_count_voltages(supply);
 	if (count < 0)
 		return count;

 	for (i = 0; i < count; i++) {
 		vdd_uV = regulator_list_voltage(supply, i);
 		if (vdd_uV <= 0)
 			continue;

 		vdd_mV = vdd_uV / 1000;
 		result |= mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV);
 	}

 	if (!result) {
 		vdd_uV = regulator_get_voltage(supply);
 		if (vdd_uV <= 0)
 			return vdd_uV;

 		vdd_mV = vdd_uV / 1000;
 		result = mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV);
 	}

 	return result;
 }

 /**
  * mmc_regulator_set_ocr - set regulator to match host->ios voltage
  * @mmc: the host to regulate
  * @supply: regulator to use
  * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
  *
  * Returns zero on success, else negative errno.
  *
  * MMC host drivers may use this to enable or disable a regulator using
  * a particular supply voltage.  This would normally be called from the
  * set_ios() method.
  */
 int mmc_regulator_set_ocr(struct mmc_host *mmc,
 			struct regulator *supply,
 			unsigned short vdd_bit)
 {
 	int			result = 0;
 	int			min_uV, max_uV;

 	if (vdd_bit) {
 		mmc_ocrbitnum_to_vdd(vdd_bit, &min_uV, &max_uV);

 		result = regulator_set_voltage(supply, min_uV, max_uV);
 		if (result == 0 && !mmc->regulator_enabled) {
 			result = regulator_enable(supply);
 			if (!result)
 				mmc->regulator_enabled = true;
 		}
 	} else if (mmc->regulator_enabled) {
 		result = regulator_disable(supply);
 		if (result == 0)
 			mmc->regulator_enabled = false;
 	}

 	if (result)
 		dev_err(mmc_dev(mmc),
 			"could not set regulator OCR (%d)\n", result);
 	return result;
 }
 EXPORT_SYMBOL_GPL(mmc_regulator_set_ocr);

 static int mmc_regulator_set_voltage_if_supported(struct regulator *regulator,
 						  int min_uV, int target_uV,
 						  int max_uV)
 {
 	int current_uV;

 	/*
 	 * Check if supported first to avoid errors since we may try several
 	 * signal levels during power up and don't want to show errors.
 	 */
 	if (!regulator_is_supported_voltage(regulator, min_uV, max_uV))
 		return -EINVAL;

 	/*
 	 * The voltage is already set, no need to switch.
 	 * Return 1 to indicate that no switch happened.
 	 */
 	current_uV = regulator_get_voltage(regulator);
 	if (current_uV == target_uV)
 		return 1;

 	return regulator_set_voltage_triplet(regulator, min_uV, target_uV,
 					     max_uV);
 }

 /**
  * mmc_regulator_set_vqmmc - Set VQMMC as per the ios
  *
  * For 3.3V signaling, we try to match VQMMC to VMMC as closely as possible.
  * That will match the behavior of old boards where VQMMC and VMMC were supplied
  * by the same supply.  The Bus Operating conditions for 3.3V signaling in the
  * SD card spec also define VQMMC in terms of VMMC.
  * If this is not possible we'll try the full 2.7-3.6V of the spec.
  *
  * For 1.2V and 1.8V signaling we'll try to get as close as possible to the
  * requested voltage.  This is definitely a good idea for UHS where there's a
  * separate regulator on the card that's trying to make 1.8V and it's best if
  * we match.
  *
  * This function is expected to be used by a controller's
  * start_signal_voltage_switch() function.
  */
 int mmc_regulator_set_vqmmc(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct device *dev = mmc_dev(mmc);
 	int ret, volt, min_uV, max_uV;

 	/* If no vqmmc supply then we can't change the voltage */
 	if (IS_ERR(mmc->supply.vqmmc))
 		return -EINVAL;

 	switch (ios->signal_voltage) {
 	case MMC_SIGNAL_VOLTAGE_120:
 		return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
 						1100000, 1200000, 1300000);
 	case MMC_SIGNAL_VOLTAGE_180:
 		return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
 						1700000, 1800000, 1950000);
 	case MMC_SIGNAL_VOLTAGE_330:
 		ret = mmc_ocrbitnum_to_vdd(mmc->ios.vdd, &volt, &max_uV);
 		if (ret < 0)
 			return ret;

 		dev_dbg(dev, "%s: found vmmc voltage range of %d-%duV\n",
 			__func__, volt, max_uV);

 		min_uV = max(volt - 300000, 2700000);
 		max_uV = min(max_uV + 200000, 3600000);

 		/*
 		 * Due to a limitation in the current implementation of
 		 * regulator_set_voltage_triplet() which is taking the lowest
 		 * voltage possible if below the target, search for a suitable
 		 * voltage in two steps and try to stay close to vmmc
 		 * with a 0.3V tolerance at first.
 		 */
 		ret = mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
 							min_uV, volt, max_uV);
 		if (ret >= 0)
 			return ret;

 		return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
 						2700000, volt, 3600000);
 	default:
 		return -EINVAL;
 	}
 }
 EXPORT_SYMBOL_GPL(mmc_regulator_set_vqmmc);

 #else

 static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
 {
 	return 0;
 }

 #endif /* CONFIG_REGULATOR */

 /**
  * mmc_regulator_get_supply - try to get VMMC and VQMMC regulators for a host
  * @mmc: the host to regulate
  *
  * Returns 0 or errno. errno should be handled, it is either a critical error
  * or -EPROBE_DEFER. 0 means no critical error but it does not mean all
  * regulators have been found because they all are optional. If you require
  * certain regulators, you need to check separately in your driver if they got
  * populated after calling this function.
  */
 int mmc_regulator_get_supply(struct mmc_host *mmc)
 {
 	struct device *dev = mmc_dev(mmc);
 	int ret;

 	mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc");
 	mmc->supply.vqmmc = devm_regulator_get_optional(dev, "vqmmc");

 	if (IS_ERR(mmc->supply.vmmc)) {
 		if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		dev_dbg(dev, "No vmmc regulator found\n");
 	} else {
 		ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc);
 		if (ret > 0)
 			mmc->ocr_avail = ret;
 		else
 			dev_warn(dev, "Failed getting OCR mask: %d\n", ret);
 	}

 	if (IS_ERR(mmc->supply.vqmmc)) {
 		if (PTR_ERR(mmc->supply.vqmmc) == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		dev_dbg(dev, "No vqmmc regulator found\n");
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(mmc_regulator_get_supply);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Helper functions for MMC regulators.
	*/

	#include <linux/device.h>
	#include <linux/err.h>
	#include <linux/log2.h>
	#include <linux/regulator/consumer.h>

	#include <linux/mmc/host.h>

	#include "core.h"
	#include "host.h"

	#ifdef CONFIG_REGULATOR

	/**
	* mmc_ocrbitnum_to_vdd - Convert a OCR bit number to its voltage
	* @vdd_bit: OCR bit number
	* @min_uV: minimum voltage value (mV)
	* @max_uV: maximum voltage value (mV)
	*
	* This function returns the voltage range according to the provided OCR
	* bit number. If conversion is not possible a negative errno value returned.
	*/
	static int mmc_ocrbitnum_to_vdd(int vdd_bit, int min_uV, int max_uV)
	{
	int tmp;

	if (!vdd_bit)
	return -EINVAL;

	/*
	* REVISIT mmc_vddrange_to_ocrmask() may have set some
	* bits this regulator doesn't quite support ... don't
	* be too picky, most cards and regulators are OK with
	* a 0.1V range goof (it's a small error percentage).
	*/
	tmp = vdd_bit - ilog2(MMC_VDD_165_195);
	if (tmp == 0) {
	min_uV = 1650 1000;
	max_uV = 1950 1000;
	} else {
	min_uV = 1900 1000 + tmp * 100 * 1000;
	max_uV = min_uV + 100 * 1000;
	}

	return 0;
	}

	/**
	* mmc_regulator_get_ocrmask - return mask of supported voltages
	* @supply: regulator to use
	*
	* This returns either a negative errno, or a mask of voltages that
	* can be provided to MMC/SD/SDIO devices using the specified voltage
	* regulator. This would normally be called before registering the
	* MMC host adapter.
	*/
	static int mmc_regulator_get_ocrmask(struct regulator *supply)
	{
	int result = 0;
	int count;
	int i;
	int vdd_uV;
	int vdd_mV;

	count = regulator_count_voltages(supply);
	if (count < 0)
	return count;

	for (i = 0; i < count; i++) {
	vdd_uV = regulator_list_voltage(supply, i);
	if (vdd_uV <= 0)
	continue;

	vdd_mV = vdd_uV / 1000;
	result \|= mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV);
	}

	if (!result) {
	vdd_uV = regulator_get_voltage(supply);
	if (vdd_uV <= 0)
	return vdd_uV;

	vdd_mV = vdd_uV / 1000;
	result = mmc_vddrange_to_ocrmask(vdd_mV, vdd_mV);
	}

	return result;
	}

	/**
	* mmc_regulator_set_ocr - set regulator to match host->ios voltage
	* @mmc: the host to regulate
	* @supply: regulator to use
	* @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
	*
	* Returns zero on success, else negative errno.
	*
	* MMC host drivers may use this to enable or disable a regulator using
	* a particular supply voltage. This would normally be called from the
	* set_ios() method.
	*/
	int mmc_regulator_set_ocr(struct mmc_host *mmc,
	struct regulator *supply,
	unsigned short vdd_bit)
	{
	int result = 0;
	int min_uV, max_uV;

	if (vdd_bit) {
	mmc_ocrbitnum_to_vdd(vdd_bit, &min_uV, &max_uV);

	result = regulator_set_voltage(supply, min_uV, max_uV);
	if (result == 0 && !mmc->regulator_enabled) {
	result = regulator_enable(supply);
	if (!result)
	mmc->regulator_enabled = true;
	}
	} else if (mmc->regulator_enabled) {
	result = regulator_disable(supply);
	if (result == 0)
	mmc->regulator_enabled = false;
	}

	if (result)
	dev_err(mmc_dev(mmc),
	"could not set regulator OCR (%d)\n", result);
	return result;
	}
	EXPORT_SYMBOL_GPL(mmc_regulator_set_ocr);

	static int mmc_regulator_set_voltage_if_supported(struct regulator *regulator,
	int min_uV, int target_uV,
	int max_uV)
	{
	int current_uV;

	/*
	* Check if supported first to avoid errors since we may try several
	* signal levels during power up and don't want to show errors.
	*/
	if (!regulator_is_supported_voltage(regulator, min_uV, max_uV))
	return -EINVAL;

	/*
	* The voltage is already set, no need to switch.
	* Return 1 to indicate that no switch happened.
	*/
	current_uV = regulator_get_voltage(regulator);
	if (current_uV == target_uV)
	return 1;

	return regulator_set_voltage_triplet(regulator, min_uV, target_uV,
	max_uV);
	}

	/**
	* mmc_regulator_set_vqmmc - Set VQMMC as per the ios
	*
	* For 3.3V signaling, we try to match VQMMC to VMMC as closely as possible.
	* That will match the behavior of old boards where VQMMC and VMMC were supplied
	* by the same supply. The Bus Operating conditions for 3.3V signaling in the
	* SD card spec also define VQMMC in terms of VMMC.
	* If this is not possible we'll try the full 2.7-3.6V of the spec.
	*
	* For 1.2V and 1.8V signaling we'll try to get as close as possible to the
	* requested voltage. This is definitely a good idea for UHS where there's a
	* separate regulator on the card that's trying to make 1.8V and it's best if
	* we match.
	*
	* This function is expected to be used by a controller's
	* start_signal_voltage_switch() function.
	*/
	int mmc_regulator_set_vqmmc(struct mmc_host mmc, struct mmc_ios ios)
	{
	struct device *dev = mmc_dev(mmc);
	int ret, volt, min_uV, max_uV;

	/* If no vqmmc supply then we can't change the voltage */
	if (IS_ERR(mmc->supply.vqmmc))
	return -EINVAL;

	switch (ios->signal_voltage) {
	case MMC_SIGNAL_VOLTAGE_120:
	return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
	1100000, 1200000, 1300000);
	case MMC_SIGNAL_VOLTAGE_180:
	return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
	1700000, 1800000, 1950000);
	case MMC_SIGNAL_VOLTAGE_330:
	ret = mmc_ocrbitnum_to_vdd(mmc->ios.vdd, &volt, &max_uV);
	if (ret < 0)
	return ret;

	dev_dbg(dev, "%s: found vmmc voltage range of %d-%duV\n",
	__func__, volt, max_uV);

	min_uV = max(volt - 300000, 2700000);
	max_uV = min(max_uV + 200000, 3600000);

	/*
	* Due to a limitation in the current implementation of
	* regulator_set_voltage_triplet() which is taking the lowest
	* voltage possible if below the target, search for a suitable
	* voltage in two steps and try to stay close to vmmc
	* with a 0.3V tolerance at first.
	*/
	ret = mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
	min_uV, volt, max_uV);
	if (ret >= 0)
	return ret;

	return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc,
	2700000, volt, 3600000);
	default:
	return -EINVAL;
	}
	}
	EXPORT_SYMBOL_GPL(mmc_regulator_set_vqmmc);

	#else

	static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
	{
	return 0;
	}

	#endif /* CONFIG_REGULATOR */

	/**
	* mmc_regulator_get_supply - try to get VMMC and VQMMC regulators for a host
	* @mmc: the host to regulate
	*
	* Returns 0 or errno. errno should be handled, it is either a critical error
	* or -EPROBE_DEFER. 0 means no critical error but it does not mean all
	* regulators have been found because they all are optional. If you require
	* certain regulators, you need to check separately in your driver if they got
	* populated after calling this function.
	*/
	int mmc_regulator_get_supply(struct mmc_host *mmc)
	{
	struct device *dev = mmc_dev(mmc);
	int ret;

	mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc");
	mmc->supply.vqmmc = devm_regulator_get_optional(dev, "vqmmc");

	if (IS_ERR(mmc->supply.vmmc)) {
	if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	dev_dbg(dev, "No vmmc regulator found\n");
	} else {
	ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc);
	if (ret > 0)
	mmc->ocr_avail = ret;
	else
	dev_warn(dev, "Failed getting OCR mask: %d\n", ret);
	}

	if (IS_ERR(mmc->supply.vqmmc)) {
	if (PTR_ERR(mmc->supply.vqmmc) == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	dev_dbg(dev, "No vqmmc regulator found\n");
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(mmc_regulator_get_supply);